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Author | Topic: Y.E.C. Model: Was there rapid evolution and speciation post flood? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
Percy writes: It is a bit dense, I will admit. The gist of it is that they looked at the sequence of each HLA allele and used a computer algorithm to predict which peptides it would bind. They then took the top 1% of predicted viral peptides and added them to the HLA proteins to see how well they bound in real life. So computer simulation predicted which peptides would bind to which alleles (which really means binding to the proteins produced by each allele), but what does the "top 1% of predicted viral peptides" mean? Does that mean predicted with the highest confidence? And then they ran laboratory experiments to see how well the predictions turned out?
From that data you can conclude that different alleles of each HLA gene bind a wide array of peptides, but not others. Not sure how to interpret this. Do you mean that some alleles bind to a wide array of peptides, and some don't?
Also, HLA proteins from different alleles bind different viral peptides. This is probably the most important information from Faith's point of view, that different alleles for the same gene bind to different viral peptides, therefore there are more than two alleles with different function. The next thing that Faith wants to know is how the connection is made between binding to different peptides and improving the performance of the immune system. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
Taq writes: The next thing that Faith wants to know is how the connection is made between binding to different peptides and improving the performance of the immune system. Although the HLA proteins were only tested against dengue virus, the same pattern carries over to other pathogens. Different alleles will bind differently to certain pathogens, changing the defenses you have against those pathogens. I believe bluegenes listed some of those examples in previous posts. I think Faith would object that you've got computer simulations and laboratory experiments that show alleles binding to different peptides, but that that's not evidence that they have different functions. Where is the evidence that allele X binding to peptide Y of dengue fever has any different effect than allele X binding to peptide Z of dengue fever? --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
NoNukes writes: For now, why isn't the blood type answer a sufficient example? I don't know why Faith answered as she did in Message 299, but the sudden capitulation is inconsistent with the rest of her posts to this thread and I don't think she's saying what she believes. I don't think either blood type or rabbit fur color proves multiple functional new alleles have come about, because multiple genes must be involved. The Wikipedia article on Blood Type says that "33 blood-group systems have been identified, including the ABO and Rh systems," which implies multiple genes at work. And I couldn't find anything about rabbit fur color earlier in the thread, but I assume it too is governed by multiple genes. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
bluegenes writes: As I pointed out in the post you're replying to, the HLA-B (one gene) alleles are well known to have very different effects in relation to different diseases. I think this is what Faith is asking for, that it be shown that alleles binding to different peptides have "different effects in relation to different diseases." --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0
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Ah, "bunnies", not "rabbits" - thanks for the reference.
...where bluegenes clearly says the varieties of fur color are from different alleles for one gene. Says it, doesn't prove it, so if you can pin it down to multiple genes more power to you. I can't pin it down in detail for rabbits, but skin/hair color in humans is governed by many genes, so the same must be true of other mammals. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
Taq writes: A change in binding specificity is a change in function by every definition used in biology. Faith is looking at outcome to determine change in function. If allele A binds to peptide X and dengue fever goes away, and if allele B binds to peptide Y and dengue fever goes away, that isn't a difference in function. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
Taq writes: Function is not a synonym for outcome. What these alleles demonstrate is that different functions can produce the same outcome. Faith will have to confirm, but I think for her the outcome she can observe is what is key. Different chemical pathways to the same outcome is a difference without a distinction for her.
More to your point, bluegenes already referenced how different alleles do result in different outcomes. For example, different alleles are more effective at fighting off malaria or HIV. Let me recount the rough details on this one. The HLA-B53 allele fights malaria, and another HLA-B allele fights another form of malaria, and other HLA-B alleles are effective against HIV. Other HLA-B alleles fight other diseases, such as dengue fever. So the HLA-B gene is an example of different alleles producing different outcomes. While researching this I came across the Wikipedia article on the History and Naming of Human Leukocyte Antigens, while includes a great deal of information about the HLA-A gene. This gene is of key significance in organ transplants. The types of HLA-A alleles must be matched as closely as possible or the organ will be rejected. Organ rejection is a substantial outcome. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
Taq writes: This is yet another example of a human gene with more than 2 alleles. Faith doesn't have a problem with more than 2 alleles. What she has a problem with is more than 2 alleles where the additional alleles do anything different than the original alleles. She claims that the new alleles must do the same things the old alleles did, i.e., have the same functions as the old alleles. She claims that the new alleles cannot have new functions. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
NoNukes writes: don't think either blood type or rabbit fur color proves multiple functional new alleles have come about, because multiple genes must be involved.
For a lot of traits, yes. But for blood type, and the particular rabbit gene in question, no. Human blood type, in particular, is determined by a single gene with three alleles. Period. I think more than just one gene must be at work, because the Wikipedia article on Blood Type says that "33 blood-group systems have been identified, including the ABO and Rh systems." The ABO and Rh systems are just the most important classifications of blood type because of their impact on transfusions - there are others. From Wikipedia:
quote: According to Wikipedia, the Kell antigen system, "is the next most common immune red cell antibody after those in the ABO and Rh system." These other blood group systems are governed by other genes and have their own alleles. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
bluegenes writes: Here's a paper that shows differences in producing immune reactions to a measles vaccine. Three HLA-B alleles are identified that perform particularly badly, and two that perform particularly well, with others in between.
Variance in HLA-B performance against measles. quote: So let me combine this with other data from the Wikipedia article on the HLA-B gene. In most cases the designation (e.g., B7) represents multiple alleles that are grouped together because of their similar function. I didn't include the broad antigens from the table at Wikipedia because I didn't understand their relationship to the antigens listed on the same line.
What this table tells us is that we know very little about which HLA-B alleles protect against which pathogens. For most of them all that is known is that they're associated with the immune system, or that they're associated with disease, which is consistent with Faith's assertion that mutations are only harmful. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
Taq writes: That was the context I was using. If Faith defines alleles by function then there are more than two alleles for that gene. I know Faith claims an original 2 alleles, so the three beta-hemoglobin alleles just force her to concede that there were an original 4 alleles maximum. Just for completeness, here are those three beta-hemoglobin alleles plus another couple I found at the Wikipedia article on HBB
The Wikipedia article says there are "numerous HBB variants", but I couldn't find more than 4 different functions, and you need more than 4 alleles with different functions. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
NoNukes writes: So there are multiple genes that affect color, but among those genes, the functionality of the c gene and its affect on how the color is expressed is well known. So you have a point regarding the system for determining fur color, and yet we still have an example to discuss. Namely, a single gene controlling an easily visible phenotypic parameter with multiple alleles at a single location. Five alleles for that particular gene have been identified. Can we get a list of those alleles and their functions?
Again if I were arguing the other side, I would point out that there are no real limits to how many rabbits were specially created so there is not a hard limit of only four total alleles for a gene as there is for humans. Perhaps for the sake of this argument, human examples are best. There's still the ark bottleneck. There could be at most four original alleles for unclean animals and 28 for clean. But I agree, human examples are best.
My argument for the ABO gene being a further example is similar. Even if ABO is not the complete picture for blood type, that gene does have a definite and functional expression on human phenotype and accordingly is a legitimate example of a gene with more than two alleles. Faith should give up on her insistence that there were an original two alleles. She has no basis for the claim, and it just makes her position unnecessarily more insensible. --Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
This is a reissue of the table of HLA-B allele groups based on information provided by Taq:
--Percy
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0 |
NoNukes writes: There is some basis. Eve was formed completely from material taken from Adam. But wouldn't God have had to change the alleles for Eve's genes, else Eve would have just been a clone of Adam? At a minimum he would have had to change the Y chromosome to an X. In creating the Eve's new X chromosome he wouldn't have just been changing alleles, he would have been creating entire new genes that don't exist on the Y chromosome. Given that we know God must have made genetic changes while creating Eve, I don't think any claims can be made as to its extent and that it must be allowed that an original gene could have had a maximum of four alleles. --Percy Edited by Percy, : Fix mixup between X and Y.
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Percy Member Posts: 22489 From: New Hampshire Joined: Member Rating: 5.0
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Okay, reissuing the table again:
This is already more than four alleles with positive effects. --Percy
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